Select the wrong pair from the following given below

Solution (By Examveda Team)

Strengite is a relatively rare iron phosphate mineral with the formula FePO₄·2H₂O.
Variscite is a hydrated aluminum phosphate mineral with the formula AlPO₄·2H₂O. it is a relatively rare phosphate mineral.
Gibbsite is one of the mineral forms of aluminium hydroxide with the chemical formula Al₂O₃·3H₂O. It is an important ore of aluminium.
Hematite is a heavy and relatively hard oxide mineral, ferric oxide (Fe₂O₃), that constitutes the most important iron ore because of its high iron content (70 percent) and its abundance.